In this contribution, Findlay offered the City of Westmount a building with a vaulted entrance, a gabled roof, and a tower with turrets on the outside; and coffered ceilings, decorative moldings, strong arches, and faux marble columns on the inside.

Its initial collection, assembled by McGill University Librarian Charles Henry Gould, numbered 2,000 books.

In 1909, the Library Committee suggested that an amount of C$20,000 be used for the creation of a space reserved for children, a reception room, and a reference service.

The library also took on the role of receiving station for magazine and book donations on the behalf of the Canadian Armed Forces.

During that same year, the Library became the curator for the entirety of the collected material of the recently established Westmount Historical Association.

[6] In 1975, the library began adding cassette tapes to its collection and offering games in the Children's Department.

In 1991, after a poll in which the citizens of Westmount approved a renewal and enlargement plan,[6] extensive work was undertaken to renovate and modernize the library.

During that time, the adult and reference collections were temporarily moved to 4225 Saint Catherine Street and the Children's Department, Audiovisual, Technical Services and Administration were located at Victoria Hall beside the library.

One of its function is to host two quality used book sales a year inside Victoria Hall.

[8] As of 2017, the library welcomes more than a thousand people daily and organizes its activities around 7,600 subscribers out of a population of 20,000 citizens.

Instead, the patron's account would be disabled after seven days until he or she either returns the item or pays a fee to replace it.

Compatible with Android and iOS, this program enables users to reserve books, search a "light" version of the catalogue, renew loans, receive notifications, and carry an electronic membership card.

In 1915, the Library Committee announced major changes to the facilities allowing easier circulation between the shelves were needed in order to offer universal access to the general public.

These were completed in the spring of 1917, when the Westmount Public Library started offering users unrestricted access to its shelves.

This involved the creation of a new workroom, the installation of concrete floors, new counters for book borrowers, and an air-conditioning system.

1959 saw major changes including the installation of new steel stacks able to contain nearly 100,000 items, a new shipping area, and a new Children's Department.

[6]The Centennial Reference Room opened in 1967 and the entire library was carpeted to help reduce noise.

[6] In 1984, the library acquired its first electronic computer, an IBM PC used as an upgrade to the automated cataloguing system.

[4] In 2023, the library relocated its adult audiovisual collection located on the ground floor to the third floor in order to free up space for a new accessible entrance facing the Westmount Park and a makerspace workshop called "the Studio"—featuring facilities for group work and other activities involving high technology, such as computer coding, robotics, and three-dimensional printing.